Trouble lighting building windows

Good Day Community.

I hope this question doesn't come across as stupid, I'm fairly new to game dev and I have a city scene that's night time. The problem I'm having is with lighting up the windows of the buildings. I'm really not sure how to go about this because obviously using actual lights would be really expensive in a city scene.

Please make me look stupid. I really feel like this is a super dumb question and the answer should be fairly simple I'm guessing?

Thanks in Advance

 

Pretty much everything you need to know is in this page of the Unity manual: https://docs.unity3d.com/Manual/StandardShaderMaterialParameterEmission.html

You'll want to create an emission map (texture) that matches up with where your windows are placed in your albedo/diffuse texture, and set that texture in the emission field of the material.

 

Use this nice free asset called MK Glow Free. Search it in the asset store and the read manual so you know how to set it up.

I use MK Glow/ Self-Illumin shader for the windows.

Here I am using it on my scene to light windows it has a glow too which is nice for foggy environments.